Wireless networks including a plurality of nodes are used for various purposes. An exemplary wireless network includes statically located nodes in a distributed environment. The nodes may include sensors for obtaining information about an environment. Such sensors include, for example, smoke detectors, detectors for detection of harmful chemicals, security breach detectors, etc. The nodes transmit data, for example, that include information obtained from the sensors, to a node designated as a base node for analysis. In some networks, a node is designated as a base node for receiving reports from a plurality of other nodes and/or for transmitting instructions to the plurality of nodes, for example, in response to analysis of data received from other nodes. Base nodes may include higher powered devices than those of other nodes. A node may be designated as a base node since it is a node with which a user may have more direct interaction than other nodes. A node may be designated as a base node for purposes of configuring a network topology. A base node, as referred to herein, is a node designated as such regardless of whether there are any inherent differences between the node and other nodes. However, inherent differences may be the designation. A node that is not designated as a base node is referred to herein as a field node. The term node without further description, as used herein, encompasses base and field nodes.
Network nodes may be organized in a number of alternative ways. One organization of nodes provides for a multihop communication, in which a node that initiates transmission of data (source node) for receipt ultimately by another node (destination node) transmits the data to intermediate nodes that pass the data on until the data is received by the destination node. For example, a field node may transmit its data to one or more intermediate nodes that transmit the data to one or more other nodes until the data is received by a base node.
Low powered devices may be used as nodes because of cost considerations. Sophisticated protocols are implemented for communication by nodes with their peers in a way that conforms to an energy budget that provides for a low rate of power consumption. The low powered devices may be battery operated and include low power radios. Power at which the radios communicate may be about 0 dBm. The low power communication renders communication susceptible to noise interference and/or attenuation. Interference may occur where multiple networks communicate via a same frequency band in a same area or in proximate areas. Particularly, where communication between a source node and a destination node, e.g., a particular field node and a base node, occurs via a communication path that includes numerous intermediate nodes, the risk of interference and attenuation rises.
While the locations at which nodes are statically installed depend on the particular system requirements for which the network is provided (for example, particular sensing needs), the system requirements may allow for flexibility in the selection of the precise locations. For a more precise determination of the locations, effects of the node layout on the risk of interference and attenuation may be considered. In this regard, a layout is chosen that provides for a number of paths over a certain predetermined threshold number between field nodes and a base node, in particular for those field nodes that communicate with the base node via intermediate nodes, i.e., indirectly. Such redundancy increases the probability of a message reaching an intended node.
For determining a layout according to which nodes are to be installed, a simulation analysis may be performed. A simulation analysis takes into account a communication range of the nodes and an overlap of the ranges in a particular layout. However, simulation analyses are inaccurate and expensive, both monetarily and with respect to time.
Accordingly, there is a need for a system and method that efficiently aids in selection of a layout for wireless multihop network nodes.